From f24b9be5957b38bb420b838115040dc2031b7d0c Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:45 -0400 Subject: net-timestamp: extend SCM_TIMESTAMPING ancillary data struct Applications that request kernel tx timestamps with SO_TIMESTAMPING read timestamps as recvmsg() ancillary data. The response is defined implicitly as timespec[3]. 1) define struct scm_timestamping explicitly and 2) add support for new tstamp types. On tx, scm_timestamping always accompanies a sock_extended_err. Define previously unused field ee_info to signal the type of ts[0]. Introduce SCM_TSTAMP_SND to define the existing behavior. The reception path is not modified. On rx, no struct similar to sock_extended_err is passed along with SCM_TIMESTAMPING. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/uapi/linux/errqueue.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include/uapi/linux/errqueue.h') diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index aacd4fb7102..accee72cae7 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -22,5 +22,23 @@ struct sock_extended_err { #define SO_EE_OFFENDER(ee) ((struct sockaddr*)((ee)+1)) +/** + * struct scm_timestamping - timestamps exposed through cmsg + * + * The timestamping interfaces SO_TIMESTAMPING, MSG_TSTAMP_* + * communicate network timestamps by passing this struct in a cmsg with + * recvmsg(). See Documentation/networking/timestamping.txt for details. + */ +struct scm_timestamping { + struct timespec ts[3]; +}; + +/* The type of scm_timestamping, passed in sock_extended_err ee_info. + * This defines the type of ts[0]. For SCM_TSTAMP_SND only, if ts[0] + * is zero, then this is a hardware timestamp and recorded in ts[2]. + */ +enum { + SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */ +}; #endif /* _UAPI_LINUX_ERRQUEUE_H */ -- cgit v1.2.3-70-g09d2 From e7fd2885385157d46c85f282fc6d7d297db43e1f Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:48 -0400 Subject: net-timestamp: SCHED timestamp on entering packet scheduler Kernel transmit latency is often incurred in the packet scheduler. Introduce a new timestamp on transmission just before entering the scheduler. When data travels through multiple devices (bonding, tunneling, ...) each device will export an individual timestamp. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/skbuff.h | 11 +++++++++-- include/uapi/linux/errqueue.h | 1 + include/uapi/linux/net_tstamp.h | 3 ++- net/core/dev.c | 4 ++++ net/core/skbuff.c | 16 ++++++++++++---- net/socket.c | 3 +++ 6 files changed, 31 insertions(+), 7 deletions(-) (limited to 'include/uapi/linux/errqueue.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0e35b3af731..50e1e9b3a5a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -229,7 +229,7 @@ enum { /* generate hardware time stamp */ SKBTX_HW_TSTAMP = 1 << 0, - /* generate software time stamp */ + /* generate software time stamp when queueing packet to NIC */ SKBTX_SW_TSTAMP = 1 << 1, /* device driver is going to provide hardware time stamp */ @@ -247,9 +247,12 @@ enum { * all frags to avoid possible bad checksum */ SKBTX_SHARED_FRAG = 1 << 5, + + /* generate software time stamp when entering packet scheduling */ + SKBTX_SCHED_TSTAMP = 1 << 6, }; -#define SKBTX_ANY_SW_TSTAMP SKBTX_SW_TSTAMP +#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | SKBTX_SCHED_TSTAMP) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) /* @@ -2695,6 +2698,10 @@ static inline bool skb_defer_rx_timestamp(struct sk_buff *skb) void skb_complete_tx_timestamp(struct sk_buff *skb, struct skb_shared_hwtstamps *hwtstamps); +void __skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, int tstype); + /** * skb_tstamp_tx - queue clone of skb with send time stamps * @orig_skb: the original outgoing packet diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index accee72cae7..17437cf297b 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -39,6 +39,7 @@ struct scm_timestamping { */ enum { SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */ + SCM_TSTAMP_SCHED, /* data entered the packet scheduler */ }; #endif /* _UAPI_LINUX_ERRQUEUE_H */ diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index 1e861d2e1a3..60733845fcd 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -21,8 +21,9 @@ enum { SOF_TIMESTAMPING_SYS_HARDWARE = (1<<5), SOF_TIMESTAMPING_RAW_HARDWARE = (1<<6), SOF_TIMESTAMPING_OPT_ID = (1<<7), + SOF_TIMESTAMPING_TX_SCHED = (1<<8), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_ID, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_SCHED, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; diff --git a/net/core/dev.c b/net/core/dev.c index b370230fe1d..1c15b189c52 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -132,6 +132,7 @@ #include #include #include +#include #include "net-sysfs.h" @@ -2876,6 +2877,9 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) skb_reset_mac_header(skb); + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP)) + __skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED); + /* Disable soft irqs for various locks below. Also * stops preemption for RCU. */ diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 0df4f1d14c5..9705c0732aa 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -3490,10 +3490,10 @@ int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) } EXPORT_SYMBOL(sock_queue_err_skb); -void skb_tstamp_tx(struct sk_buff *orig_skb, - struct skb_shared_hwtstamps *hwtstamps) +void __skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps, + struct sock *sk, int tstype) { - struct sock *sk = orig_skb->sk; struct sock_exterr_skb *serr; struct sk_buff *skb; int err; @@ -3521,7 +3521,7 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, memset(serr, 0, sizeof(*serr)); serr->ee.ee_errno = ENOMSG; serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; - serr->ee.ee_info = SCM_TSTAMP_SND; + serr->ee.ee_info = tstype; if (sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) serr->ee.ee_data = skb_shinfo(skb)->tskey; @@ -3530,6 +3530,14 @@ void skb_tstamp_tx(struct sk_buff *orig_skb, if (err) kfree_skb(skb); } +EXPORT_SYMBOL_GPL(__skb_tstamp_tx); + +void skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps) +{ + return __skb_tstamp_tx(orig_skb, hwtstamps, orig_skb->sk, + SCM_TSTAMP_SND); +} EXPORT_SYMBOL_GPL(skb_tstamp_tx); void skb_complete_wifi_ack(struct sk_buff *skb, bool acked) diff --git a/net/socket.c b/net/socket.c index 255d9b80272..3a2778d7163 100644 --- a/net/socket.c +++ b/net/socket.c @@ -617,6 +617,9 @@ void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags) *tx_flags |= SKBTX_HW_TSTAMP; if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SOFTWARE) *tx_flags |= SKBTX_SW_TSTAMP; + if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED) + *tx_flags |= SKBTX_SCHED_TSTAMP; + if (sock_flag(sk, SOCK_WIFI_STATUS)) *tx_flags |= SKBTX_WIFI_STATUS; } -- cgit v1.2.3-70-g09d2 From e1c8a607b28190cd09a271508aa3025d3c2f312e Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Mon, 4 Aug 2014 22:11:50 -0400 Subject: net-timestamp: ACK timestamp for bytestreams Add SOF_TIMESTAMPING_TX_ACK, a request for a tstamp when the last byte in the send() call is acknowledged. It implements the feature for TCP. The timestamp is generated when the TCP socket cumulative ACK is moved beyond the tracked seqno for the first time. The feature ignores SACK and FACK, because those acknowledge the specific byte, but not necessarily the entire contents of the buffer up to that byte. Signed-off-by: Willem de Bruijn Signed-off-by: David S. Miller --- include/linux/skbuff.h | 7 ++++++- include/uapi/linux/errqueue.h | 1 + include/uapi/linux/net_tstamp.h | 3 ++- net/ipv4/tcp_input.c | 6 ++++++ net/socket.c | 2 ++ 5 files changed, 17 insertions(+), 2 deletions(-) (limited to 'include/uapi/linux/errqueue.h') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 50e1e9b3a5a..11c270551d2 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -250,9 +250,14 @@ enum { /* generate software time stamp when entering packet scheduling */ SKBTX_SCHED_TSTAMP = 1 << 6, + + /* generate software timestamp on peer data acknowledgment */ + SKBTX_ACK_TSTAMP = 1 << 7, }; -#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | SKBTX_SCHED_TSTAMP) +#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \ + SKBTX_SCHED_TSTAMP | \ + SKBTX_ACK_TSTAMP) #define SKBTX_ANY_TSTAMP (SKBTX_HW_TSTAMP | SKBTX_ANY_SW_TSTAMP) /* diff --git a/include/uapi/linux/errqueue.h b/include/uapi/linux/errqueue.h index 17437cf297b..07bdce1f444 100644 --- a/include/uapi/linux/errqueue.h +++ b/include/uapi/linux/errqueue.h @@ -40,6 +40,7 @@ struct scm_timestamping { enum { SCM_TSTAMP_SND, /* driver passed skb to NIC, or HW */ SCM_TSTAMP_SCHED, /* data entered the packet scheduler */ + SCM_TSTAMP_ACK, /* data acknowledged by peer */ }; #endif /* _UAPI_LINUX_ERRQUEUE_H */ diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index 60733845fcd..ff354021bb6 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -22,8 +22,9 @@ enum { SOF_TIMESTAMPING_RAW_HARDWARE = (1<<6), SOF_TIMESTAMPING_OPT_ID = (1<<7), SOF_TIMESTAMPING_TX_SCHED = (1<<8), + SOF_TIMESTAMPING_TX_ACK = (1<<9), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_SCHED, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_TX_ACK, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 6a298450775..a3d47af0190 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -74,6 +74,7 @@ #include #include #include +#include int sysctl_tcp_timestamps __read_mostly = 1; int sysctl_tcp_window_scaling __read_mostly = 1; @@ -3106,6 +3107,11 @@ static int tcp_clean_rtx_queue(struct sock *sk, int prior_fackets, tp->retrans_stamp = 0; } + if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_ACK_TSTAMP) && + between(skb_shinfo(skb)->tskey, prior_snd_una, + tp->snd_una + 1)) + __skb_tstamp_tx(skb, NULL, sk, SCM_TSTAMP_ACK); + if (!fully_acked) break; diff --git a/net/socket.c b/net/socket.c index 3a2778d7163..ae89569a2db 100644 --- a/net/socket.c +++ b/net/socket.c @@ -619,6 +619,8 @@ void sock_tx_timestamp(struct sock *sk, __u8 *tx_flags) *tx_flags |= SKBTX_SW_TSTAMP; if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_SCHED) *tx_flags |= SKBTX_SCHED_TSTAMP; + if (sk->sk_tsflags & SOF_TIMESTAMPING_TX_ACK) + *tx_flags |= SKBTX_ACK_TSTAMP; if (sock_flag(sk, SOCK_WIFI_STATUS)) *tx_flags |= SKBTX_WIFI_STATUS; -- cgit v1.2.3-70-g09d2